A conventional image sensing module is disclosed in FIG. 7 and generally includes a chip base 81 with an image sensing chip 82 connected thereon and the legs 811 of the base 81 are connected to the chip 82 by wires. A frame 83 and a glass plate 84 pack the base 81 so as to form the image sensor 8. The image sensing sensor 8 includes a lens assembly 91 which includes a lens tube 92 with lenses 93 therein.
Due to the connection by wires between the image sensor 8 and the chip 82, the processes for manufacturing are complicated and the image sensor 8 cannot reach a satisfied thickness.
FIG. 8 shows a Taiwanese publish number 572528 which discloses a plurality of metal plates 72 on a base 71 which has a recess 73 defined in an underside thereof. An image sensing chip 74 is received in the recess 73 and are electrically connected to the metal plates 72. A chamber 75 communicates with the recess 73 and a glass plate 76 is connected to the under side of the chamber 75 and a lens tube 77 is threadedly connected to the chamber 75. The lens tube 77 includes lenses 78 so as to form the image sensing module.
The disclosed module directly pack the chip 74 to the base 71 without the frame and the chip base so as to reduce the thickness of the module.
However, the image sensing area of the chip 74 is located close to one side of the glass plate 76. In other words, the image sensing area of the chip 74 is exposed to air before the glass plate 76 is mounted so that the image sensing area of the chip 74 might be contaminated. The chip 74 is sent to test after it is packed within the bas 71, once a defect is found in the chip 74, the whole assembly of the chip 74 and the base 71 have to be discarded. There are several steps to install the chip 74 in the recess 73 of the base 71 and to cover the glass plate 76 onto the chamber 75, too many steps are required. A flange 79 is located between the recess 73 and the chamber 75 so as to allow the glass plate 76 to be engaged with the chamber 75, the thickness of the flange 79 contributes a certain thickness of the module.
A technique called “Flip Chip” is used widely in the Liquid Crystal Device monitors and relates to a technique to directly connected the chip on the glass plate. Wires are arranged on the glass plate to be connected with the chip and the wires are as thin as 3.5 mm2 and are as many as billions of wires. Although the technique of “Flip Chip” can be used in the image sensing module, and the chip can be directly connected on the glass plate to reduce the thickness, the wires are so thin which are difficult to be connected to the circuit boards (PCB or FPC). Therefore, there is not such application used in the image sensing modules.
The present invention intends to provide an image sensing module that uses the technique of “Flip Chip”.